This is happening because our docker has support for more than just a root namespace (i.e. docker.io), you have have multiple root namespaces where you get images from and docker images is correctly showing where the image came from.

(In reply to Florin from comment #2)
> But in this case, if I have a repository
> "docker.io/resin/armv7hf-supervisor", if I issue a "docker images
> resin/armv7hf-supervisor" this will not return anything
docker 1.10.2 isn't affected by this:
$ docker tag busybox docker.io/resin/armv7hf-supervisor
$ docker images resin/armv7hf-supervisor
REPOSITORY TAG IMAGE ID CREATED SIZE
docker.io/resin/armv7hf-supervisor latest 3240943c9ea3 12 days ago 1.114 MB
could you try this yourself and see if it works? the update is available in the updates-testing repository https://bodhi.fedoraproject.org/updates/FEDORA-2016-e63d91c106